spring mvc : servlet - http message body(json)

spring-mvc/servlet/src/main/java/com/example/servlet/basic/HelloData.java

@@ -0,0 +1,11 @@
+package com.example.servlet.basic;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter @Setter
+public class HelloData {
+
+    private String username;
+    private int age;
+}

spring-mvc/servlet/src/main/java/com/example/servlet/basic/request/RequestBodyJsonServlet.java

@@ -0,0 +1,33 @@
+package com.example.servlet.basic.request;
+
+import com.example.servlet.basic.HelloData;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.springframework.util.StreamUtils;
+
+import javax.servlet.ServletException;
+import javax.servlet.ServletInputStream;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+
+@WebServlet("/request-body-json")
+public class RequestBodyJsonServlet extends HttpServlet {
+
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
+    @Override
+    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+        ServletInputStream inputStream = request.getInputStream();
+        String messageBody = StreamUtils.copyToString(inputStream, StandardCharsets.UTF_8);
+        System.out.println("messageBody = " + messageBody);
+
+        HelloData helloData = objectMapper.readValue(messageBody, HelloData.class);
+        System.out.println("helloData.username = " + helloData.getUsername());
+        System.out.println("helloData.age = " + helloData.getAge());
+
+        response.getWriter().write("ok");
+    }
+}